Recent developments in metallic beverage container body decorating allow manufacturers to produce consecutively decorated beverage container bodies having unique finished art relative to each other on a single dry offset beverage container body decorator. Prior to these recent developments, consecutively decorated beverage container bodies exhibited identical finished art. Some of these recent developments are disclosed in U.S. Patent Application Publication No. 2015/0174891 A1 corresponding to U.S. application Ser. No. 14/412,585, which is hereby incorporated by reference as if fully set for herein and for a particular purpose of describing the dry rotary offset printing process as it relates to metallic beverage container bodies for two-piece beverage containers.
In a typical dry rotary offset beverage container body decorator, cartridges are supplied with colored ink that is eventually applied onto a cylindrical side wall of the metal beverage container body. The printing apparatus is provided with an ink cartridge for each color that one wishes to apply onto the metal beverage container body.
The ink cartridges supply ink to printing plates, which have art in relief corresponding to finished art to be printed onto the metal beverage container. This finished art may be a text, a figure, or any type of graphic which one wishes to make on a metal beverage container. Thus, it is very important to position the printing plate correctly relative to the metal beverage container and the ink cartridges.
It is also important to note that the relief art present on the printing plates is in high relief wherein ink supplied to the art in high relief on the printing plates transfers to a transfer blanket. This transfer blanket is an ink transferring means between the printing plates and the metal beverage container to be printed, generally produced from a rubber, rubber-like, or other pliable material.
The ink-laden relief features on each printing plate come into contact with a single transfer blanket. Thus, each transfer blanket receives ink from a plurality of printing plates to produce a finished artwork design. This is carried out by rotation of a printing plate, which transfers the ink present in relief to the transfer blanket, which is fixed on a transfer blanket drum, which has a rotation synchronized with (i) the metal beverage container bodies to be printed, (ii) the positioning of the transfer blankets that are on the surface of the transfer blanket drum, and (iii) the printing plates.
Each beverage container body engages just one transfer blanket to receive a complete finished art design of multiple colors that the transfer blanket has received from a plurality of printing plates.
The synchronization between aforementioned elements makes it possible to decorate the metal beverage container bodies in a precise manner. This is of the utmost importance in metal beverage container printing. There should be no overlapping of the print on the metal beverage container when it receives ink corresponding to the art exhibited by the plurality of printing plates from a single transfer blanket.
In other words, the art on a first printing plate will transfer ink only to a predetermined area of a first transfer blanket. A second printing plate will transfer ink on its surface to another area on the first transfer blanket that did not receive ink from the first printing plate, and so on. This is dependent on the number of printing colors on the metal beverage containers.
Thus, printing of an entire metal beverage container cylindrical surface without ink overlapping is possible using this type of rotary dry offset printing apparatus. In this regard, it should be stressed that there is transfer of more than one art, each having a different color to a single transfer blanket on the transfer blanket drum from more than one printing plate, each in communication with a respective ink-cartridge. Upon continuous rotation of the transfer blanket drum, the blanket comes into contact with the metal beverage container cylindrical surface to be printed. Thus, each blanket fully decorates one metal beverage container body upon rotation of the drum.
The recent improvement in beverage container body decorating includes providing art in the form of relief features on the transfer blankets. Thus, rather than having a single flat surface that receives ink from the printing plates, each transfer blankets has art in relief, typically low relief engravings or cooperating regions in high and low relief, to produce differing final images on consecutively decorated metallic beverage container bodies on a dry offset rotary beverage container body decorator.
Because the transfer blankets are produced from a softer material, such as rubber or a material having a cushioning elastic-like quality, the decorating process can result in print anomalies or defects associated with transfer blanket physical properties, difficulties in registration between the printing blankets or the container bodies, and simple wear and tear. There exists, therefore, a need to inspect decorated beverage container bodies as soon as practicable in the container body manufacturing process. The problem addressed by the inventors can be stated as follows: How to inspect metallic beverage container bodies during a beverage container body manufacturing process as soon after the container bodies have been decorated.
The present invention is provided to solve the problems discussed above and other problems, and to provide advantages and aspects not provided by prior beverage container body manufacturing processes of this type. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.